Question

Question 1
What is a good source of energy?

Answer 1

A good source of energy fulfils the following criteria:
$\to$ It produces a lot of heat per unit mass.
$\to$ It does a huge amount of work per unit mass.
$\to$ It is easily accessible.
$\to$ It is easy to store and transport.
$\to$ It is economical.
$\to$ It produces less amount of smoke.